Definition ofspecies specific andcross-reactive antigenic determinants ofMycobacterium leprae using monoclonal antibodies

SUMMARY Foursoluble antigens ofMycobacterium leprae havebeenidentified using 12murine monoclonal antibodies. Their specificity, taxonomic distribution andmolecular nature wereanalysed byradioimmunoassays andbyimmunoblotting frompolyacrylamide electrophoresis gels. A protein antigen MYl (12K)reacted withoneantibody (ML06) without demonstrable cross-reactivity foranyoftheother20tested species of mycobacteria. Another fourantibodies whichidentified antigen MY2 revealed onlya marginal degree ofcross-reactivity withthree other species ofmycobacteria. Twoantigens shared byseveral other mycobacteria species were: MY3represented byfive protein bands (35-70K) andasubtilisin resistant molecule MY4 (40-50K) withtwodistinct determinants andpresumably ofpolysaccharide nature. Thedescribed monoclonal antibodies mayrepresent novel valuable diagnostic reagents aswell astools forthepurification of antigens whichcould beexplored towards prophylactic ortherapeutic immunization against leprosy.